Downhole motors are invariably used in tandem with a universal joint connection to a bearing assembly when drilling through rock formations. The bearing assembly translates the eccentric motion of the downhole motor to concentric motion, and assists in bearing radial and axial loading during the drilling operations.
When the drill bit becomes stuck while drilling, it is not possible to rotate the drill string to the right to dislodge the drill bit without overriding and potentially damaging the downhole motor. By rotating the drill string to the right, increased torque can be provided directly to the drill bit to increase the chances of breaking the drill bit loose from its "stuck" position. This is one of a number of situations, in which it would be advantageous to rotate the drill string to the right.